Current Grading Systems

More than 15 grading systems and return-to-play parameters have been published to guide the team physician, trainer, and coach in the evaluation and management of concussion. However, because of a lack of scientific foundation, these recommendations and grading systems are relatively arbitrary guides.

For example, most concussion grading systems determine return-to-play decisions based on the presence and duration of loss of consciousness or amnesia, but neither symptom is necessary for an injury to be classified as a concussion.

The Cantu guidelines are based on the experience of a clinical neurosurgeon as well as a review of the literature. The Colorado guidelines were generated by members of the Colorado Medical Society after the death of an athlete from an on-field head injury. These criteria mandate that any loss of consciousness is considered to be a grade 3 concussion and should be treated as a severe injury.

The Colorado guidelines were amended by the American Academy of Neurology (AAN) in 1997; these criteria permit return-to-play following a grade 1 concussion if the athlete is asymptomatic 15 minutes after the episode.

These grading systems have promoted consistent terminology and a framework to assess severity of concussion, but concern remains that little data support the criteria established by the grading systems. Because the concussion guidelines are not evidence based, concussion is difficult to categorize, and reliable return-to-play decisions are challenging.